I live in that area and can tell you that there are no campgrounds any closer than an 45 minutes to an hours drive away even in NJ. (Well that really depends on what time of day you are driving, rush hour is brutal). Sesame place is located in a very populated area in Langhorne right off of Route 1. The closest campgrounds would be Colonial Woods or Beaver Valley Campground in Ottsville. There are a couple in Quakertown as well such as Ringing Rocks and Quaker Woods, but they are not as nice. I have been to all of them. Colonial Woods is nice, has a lot of things to do for kids, but can be loud and crowded and a lot of the sites are very close together. Beaver Valley is a little closer and is the best campground in the area. It is very well maintained and usually pretty quiet and most of the sites are very large. I have been going there since i was a kid and i am now 45. We spend every weekend in the fall there. You are also close to Dorney Park in Allentown as well. However if you are going to Great Adventure, you may be able to find something in between the two parks. I am not very familiar with that area as far as camping in concerned.